expose PHP opcache via environment variable for different workload

php/Dockerfile

@@ -19,6 +19,15 @@ RUN source /os-release && \
     --path /install_root --statedir /swupd-state \
     --bundles=os-core-update,php-basic --no-boot-update
 
+RUN echo -e '\
+opcache.enable_cli=${OPCACHE_ENABLE_CLI}\n\
+opcache.memory_consumption=${OPCACHE_MEMORY_CONSUMPTION}\n\
+opcache.validate_timestamps=${OPCACHE_VALIDATE_TIMESTAMPS}\n\
+opcache.max_accelerated_files=${OPCACHE_MAX_ACCELERATED_FILES}\n\
+opcache.optimization_level=${OPCACHE_OPTIMIZATION_LEVEL}\n\
+opcache.interned_strings_buffer=${OPCACHE_INTERNED_STRINGS_BUFFER}\n\
+opcache.revalidate_freq=${OPCACHE_REVALIDATE_FREQ}' >> /install_root/usr/share/defaults/php/php.ini
+
 # For some Host OS configuration with redirect_dir on,
 # extra data are saved on the upper layer when the same
 # file exists on different layers. To minimize docker
@@ -28,9 +37,16 @@ COPY --from=clearlinux/os-core:latest / /os_core_install/
 RUN cd / && \
     find os_core_install | sed -e 's/os_core_install/install_root/' | xargs rm -d &> /dev/null || true
 
-
 FROM clearlinux/os-core:latest
 
+ENV OPCACHE_REVALIDATE_FREQ=0 \
+    OPCACHE_VALIDATE_TIMESTAMPS=0 \
+    OPCACHE_ENABLE_CLI=1 \
+    OPCACHE_OPTIMIZATION_LEVEL=0x7FFFFFFF \
+    OPCACHE_MEMORY_CONSUMPTION=256 \
+    OPCACHE_MAX_ACCELERATED_FILES=10000 \
+    OPCACHE_INTERNED_STRINGS_BUFFER=16
+
 COPY --from=builder /install_root /
 
 CMD ["php","-a"]

php/README.md

@@ -54,9 +54,71 @@ image](https://hub.docker.com/_/php).
     docker run -it --rm --name my-running-php clearlinux/php
     ```
 
+3. Customize OPCache parameters via environment variable, for example:
+   ```
+   docker run -it -e "OPCACHE_ENABLE_CLI=1" clearlinux/php
+   ```
+   *Note: please get all environment variable setting from  below OPCache parameters section.*
+
 <!-- Optional -->
 ### Deploy with Kubernetes
 
+<!-- Optional -->
+### OPCache Configurations
+The OPCache parameters for PHP container could be configed via following environment variable.
+These values will be set into /usr/share/defaults/php/php.ini.
+
+* **OPCACHE_ENABLE_CLI**
+   - Default Value: 1
+   - Config in php.ini: opcache.enable_cli
+   - Descriptions:
+     Enables the opcode cache for the CLI version of PHP. When testing/debugging or
+     run **PHPBench**, set 1
+
+* **OPCACHE_VALIDATE_TIMESTAMPS**
+   - Default Value: 0
+   - Config in php.ini: opcache.validate_timestamps
+   - Descriptions:
+     If enabled, OPcache will check for updated scripts every opcache.revalidate_freq seconds.
+     If the source of workload is cloned by git via sidecar design pattern and will be updated
+     often, set 1
+
+* **OPCACHE_REVALIDATE_FREQ**
+   - Default Value: 0
+   - Config in php.ini: opcache.revalidate_freq
+   - Descriptions:
+     How often to check script timestamps for updates, in seconds. 0 will result in
+     OPcache checking for updates on every request.
+
+* **OPCACHE_INTERNED_STRINGS_BUFFER**
+   - Default Value: 16
+   - Config in php.ini: opcache.interned_strings_buffer
+   - Descriptions:
+     The amount of memory used to store interned strings, in megabytes.
+
+* **OPCACHE_OPTIMIZATION_LEVEL**
+   - Default Value: 0x7FFFFFFF
+   - Config in php.ini: opcache.optimization_level
+   - Descriptions:
+     A bitmask that controls which optimisation passes are executed.
+
+* **OPCACHE_MEMORY_CONSUMPTION**
+   - Default Value: 256
+   - Config in php.ini: opcache.memory_consumption
+   - Descriptions:
+     The size of the shared memory storage used by OPcache, in megabytes.
+     You can use the function opcachegetstatus() to tell how much memory opcache
+     is consuming and if you need to increase the amount
+
+* **OPCACHE_MAX_ACCELERATED_FILES**
+   - Default Value: 10000
+   - Confg in php.ini: opcache.max_accelerated_files
+   - Descriptions:
+     Controls how many PHP files, at most, can be held in memory at once. It's important
+     that your project has LESS FILES than whatever you set this at.
+     You can run `find . -type f -print | grep php | wc -l` to quickly calculate the number
+     of files in your codebase.
+
 <!-- Required -->
 ## Build and modify: